With regard to lavage solutions for the intestinal tract, examples of known ones are a combination of polyethylene glycol or mannitol with an electrolyte [Gastroenterology, 78, 991 (1980)], a combination of polyethylene glycol and xylose with an electrolyte [Gasteroenterology, 79, 35 (1980)], a combination of polyethylene glycol with an electrolyte [Gastroenterology, 84, 1512 (1981) and Japanese Laid-Open Patent Publications Sho-63/500523 (PCT), Hei-01/125319, Hei-01/132527 and Hei-02/292223], a combination of at least one water-soluble high-molecular weight compound selected from polyethylene glycol, dextran, dextrin, hydroxyetliyl starch, polydextrose, gum arabic and pectin with an electrolyte (Japanese Laid-Open Patent Publication Hei-03/284620), a combination of erythritol and/or xylitol with an electrolyte (Japanese Laid-Open Patent Publication Hei-03/284620), a combination of fructo-oligosaccharide with an electrolyte (Japanese Laid-Open Patent Publication Hei-03/291228), and a combination of at least one compound selected from lactitol, maltitol and carboxymethyl cellulose with an electrolyte (Japanese Laid-Open Patent Publication Hei-05/255092).
However, such a lavage solution for the intestinal tract which is in a liquid form of a composition for cleaning the intestinal tract is very viscous and, therefore, foam is apt to be generated in the intestines upon its application or administration and, in addition, the generated foam hardly disappears therein. Accordingly, such solution has a disadvantage that satisfactory observation in the test or operation is disturbed or, due to its adhesion onto a lens of a camera, precise diagnosis is not possible. In view of the above, it is necessary in actual clinical practice to administer an antifoaming agent to a patient prior to a clinical test or surgery for removing the foam which is generated by the use of the lavage solution.
The present inventors tried to develop a lavage solution for the intestinal tract wherein an antifoaming agent is added to a conventional lavage solution for the intestinal tract in order to solve the above-mentioned difficulties in practical use. However, there was a problem that the liquid phase was separated into an aqueous phase and oily phase whereby the effect of the antifoaming agent was not achieved.
An object of the present invention is to provide a lavage solution for the intestinal tract that is more easily applicable, hardly generates foam in practical use and is stable as a pharmaceutical preparation.